1. Field of the Invention
The present invention relates to a disc player for reproducing both a minidisc and a compact disc and more particularly, to a disc player for reproducing both a minidisc and a compact disc by using a single pickup device.
2. Description of the Prior Art
Nowadays, a variety of disc players are used for reproduction of only one kind of disc. So, when a user wants to obtain some information from other kinds of discs, e.g., minidisc (MD) and compact disc (CD), he may be required to buy a new disc player applicable thereto. Also, although in general compact disc player (CDP), there have been manufactured disc players which can play discs with different sizes, e.g. CD and laser disc (LD), that may be used only in case of a reproduction of the same kind of disc. Lately, a disc player capable of playing a naked disc as well as a cartridge-encased disc (hereinafter, cartridge) like the above players has been proposed. Such player capable of reproducing both the naked disc and the cartridge-encased disc is disclosed in U.S. Pat. No. 5,299,185. The structure and operation of the disc player as an example are described as follows.
FIG. 1 is a perspective view for illustrating a state of a disc player loading a naked disc and reading out some data. As shown in the figure, the conventional disc player includes a disc tray 20 for receiving a naked disc 100; a cartridge carrying device for carrying a cartridge 110; a chucking device for chucking naked disc 100; a turntable for driving naked disc 100 and cartridge 110; sensors for sensing positions of the above components; and a controller for controlling positions of the above components. The disc player further includes a mouth panel 3 for insertion and ejection of naked disc 100 and cartridge 110.
First of all, process of loading and driving naked disc 100 by the disc player will be explained. When an eject switch is pushed, a lid 70 is pivoted upward to open a slot 4 of mouth panel 3. An electric motor 38 of a disc tray driving mechanism 30 is also energized to rotate in one direction, so that disc tray 20 is moved forward from the standby position (not shown) and ejected through slot 4 in a mouth panel 3 direction (hereinafter, front direction).
Naked disc 100 is put on a disc placing depression (not shown) formed on disc tray 20. When the eject switch is again pushed, electric motor 38 is energized to rotate in the other direction, so that disc tray 20 slides into a housing (not shown) together with naked disc 100 in the same manner as that of a conventional disc tray carrying member. Since a pivotal chassis (not shown) is kept in the lower position, the inward movement of disc tray 20 is smoothly carried out without being blocked by a turntable and an optical pickup (not shown). When disc tray 20 comes to the given position where a bent portion 25A of a connecting plate 25 secured to disc tray 20 faces a photo sensor 41, sensor 41 senses that disc tray 20 has reached the loading-completed position and stops electrical motor 38. When a third photo sensor (not shown) which is positioned just below a peephole of disc tray 20 senses that naked disc 100 is present on the disc placing depression, the motor (not shown) is energized to cause a first cylindrical cam (not shown) and a second cylindrical cam 56 to turn in a given direction. The pivotal chassis is pivoted upward to the upper position lifting the turntable and the optical pickup to their working positions and at the same time, a chucking arm 60 is pivoted downward to its working position. Then, naked disc 100 is rotatably clamped by a chucking plate 64 of chucking arm 60.
Under this condition, when a play start switch (not shown) is pushed, the turntable is driven by a spindle motor (not shown) for turning naked disc 100 and the optical pickup is moved radially for reading information from naked disc 100. After stopping the reading of information from naked disc 100, disc tray 20 is ejected outside by the eject switch. At that time, disc tray 20 from which naked disc 100 is removed is inserted into the housing and stopped at the standby position.
Next, a process for insertion of cartridge 110 will be explained. FIG. 2 is a plan view for illustrating a state of loading and playing the cartridge in the disc player of FIG. 1. Before cartridge 110 is inserted into the disc player, disc tray 20 is always at the standby position. Without using the eject switch, cartridge 110 can be manually inserted into slot 4 without being obstructed by disc tray 20. The structure of a second cam groove 56B of second cylindrical cam 56 does not obstruct the opening of lid 70. When cartridge 110 comes to a given position in the housing, a shutter 113 of cartridge 110 is brought into abutment with a roller 98 of a shutter opening arm 96. Thus, the subsequent inward movement of cartridge 110 causes roller 98 to open shutter 113. During this operation, shutter opening arm 96 is pivoted counterclockwise about first pivot shaft 95 against a spring 99. When cartridge 110 is further inserted into the housing, the leading right corner of a cartridge 110 comes to abutment with a pawl part 88A of a hook lever 88 causing a pivoting movement of hook lever 88 about a pivot shaft 89. A pint 88B of hook lever 88 is inserted into a recess 111 formed in cartridge 110 and pin 88B of hook lever 88 gets over a projection of a flip-flop lever 85, so that hook lever 88 clamps cartridge 110 with an aid of the flip-flop lever biased by a spring 86. When inserting cartridge 110 into the housing, the external force applied to cartridge 110 is transmitted to a link 82 through second pivot shaft 87, so that link 82 is moved rearwardly. The rearward movement of link 82 draws the cartridge 110 deeply into the housing due to the latched engagement between the cartridge 110 and the hook lever 88 mounted on the link 82. As a result, when disc tray 20 is present at the rearmost position, a photo sensor 45 operates to deenergize motor 38 shown in FIG. 1 to stop disc tray 20. Upon completion of the loading for cartridge 110, the third sensor (not shown) senses that cartridge 110 is present at the given position in the housing. A motor (not shown) is energized for the player to read out data from cartridge 110 through the similar process to that performed after completion of the loading of naked disc 100.
The disc player described the above can make playback of both naked disc and cartridge but can not reproduce two kinds of discs with different sizes such as minidisc and compact disc at the same time. Further, components for the loading and the driving of the naked disc and the cartridge are very complicatedly connected thereto, so that the reliability for the entire components may be seriously considered. Due to these components, the production cost is also increased.